Adjustable guiding cam mechanism



Sept 12, 1961 c. J. M. BENINK ETAL 2,999,471

ADJUSTABLE GUIDING CAM MECHANISM Filed Sp1.. 30, 1957 linited StatesPatent G 2,999,471 ADJUSTABLE GUIDING CAM MECHANISM Christiaan JosephMarinus Benink and Herbert Wenz, Kaiserslautern, Pfalz, Germany,assiguors to G. M. Pfad AG., Kaiserslautern, Pfalz, Germany Filed Sept.30, 1957, Ser. No. 687,139 Claims priority, application Germany Oct. 9,1956 Claims. (Cl. 112-158) The invention relates to sewing machines ofthe zig-zag type and is more particularly concerned with a device forsewing decorative stitches, which comprises nests of pattern camsarranged upon a common rotatable shaft which control the lateraldeections of the needle and also the stitch length for the forward andreverse stitches. A mechanism of the type in which the present inventionmay be utilized to advantage is illustrated in applicants copendingapplication Ser. No. 687,730, tiled October 2, 1957, now U.S. Patent No.2,887,968.

In sewing machines for decorative stitches known heretofore in which thestitch length is guided in addition to the lateral needle detlections,only one pattern cam disk is provided for the stitch length because thelever serving for transmitting the guiding movements to the feed dog isrockable only in ione plane due to structural limitations. It" it isdesired to set up a pattern having a different stitch length, it isnecessary to exchange the pattern cam disk for a different one.

It is an object of the invention to provide the possibility ofoptionally selecting among a plurality of mounted pattern disks for thestitch length fone disk for producing a plurality of patterns with thecombination of one pattern disk for the stitch length and a pattern diskfor the lateral needle deflections.

In accordance with the invention a plurality of pattern disks for thestitch length assembled in a nest are adjustable axially as well as intheir circumferential relationship with respect to a follower which ismovable in a plane and with respect to the pattern cam nest for thelateral needle dellections for selecting one pattern disk for the stitchlength and for setting up an optional displacement of the guiding phasesbetween both nests of cams.

For this purpose one of the nests of pattern cam disks is provided withspacing studs which are evenly distributed around a circle which isconcentric with respect to the axis of rotation. These studs are adaptedto engage corresponding groups of holes in the other nest of disks ofdifferent depths as well as of any desired number and distribution. Thedifferent depths of the individual groups of holes may for this purposebe a multiple of the thickness of the cam disks for the stitch lengths.

Other objects and advantageous features of the invention will becomemore apparent from the following description of an embodiment of theinvention which is illustrated in the accompanying drawing in which:

FIG. l is a front view yof a sewing machine provided with the device inaccordance with the invention;

FIG. 2 is a partial sectional view to an enlarged scale exposing thedevice in accordance with the invention;

FIG. 3 is a top view of the nest of pattern disks;

FIG. 4 is a cross section of the nests of disks taken along line IV-IVof FIG. 3; and

FIG. 5 is a view of the nested disks partly in section.

FIG. l generally illustrates the machine comprising the base plate 1,standard 2, arm 3 and head 4. The arm shaft 5 is journalled in the usualmanner in the arm of the machine carrying the balance wheel 6 on itsoutwardly extending end and operatively connected at its other end tothe reciprocable needle bar 7 which is arranged for deflection laterallyto two sides. The lateral needle deiiections can be controlled in aknown manner by means of the stitch width setting lever 8 and the stitchlocation adfice 2 justing lever 9. The mechanism for adjusting thestitch length which is operated by means of lever 10 is provided in thestandard of the machine. The transmission bar 11 (FIG. 2) may also becoupled in a known manner to the stitch length setting means (not shown)by means of the setting lever 10 for automatically controlling thestitch length. The transmission bar 11 is mounted for pivotal movementabout a pivot member 12 which is pivotally mounted in one arm 13 of anangular lever 14 which, in turn, is rockable on a. pivot member 15secured in blocks 17 secured to a base plate 16. A link member 19 whichis turned on itself at an angle of is joined by means of a screw 20 tothe other arm 18 of angular lever 14, and the other end of the linkmember is joined by means of screw 21 to the offset arm 22 of therockable lever 23. The lever 23 is rockable in a horizontal plane abouta collar or pivot screw 24 and carries the follower member 26 endwise ofa further offset arm 2S (see also FIG. 3). When the automatic control iscut in by means of shifting lever 10 the follower 26 is brought intoengagement with the upper of the two pattern disks 27 and 2S providedfor controlling the stitch length. The pattern disks are rotated in aknown manner by way of a worm gear or the like (not shown) from the armshaft 5 and a shaft 29 (FIG. 4). Shaft 29 is journalled in a stub 31 onthe vbase plate 16 by means or' screws 30. A tubular support member 33having a carrier pin 34 is provided upon Shaft 29 and secured thereto bymeans of a screw 32. A

sleeve 35 is slidingly received on the support member 33, having securedthereto cam disks 36 for guiding the lateral needle deflections, saidcam disks being carried along by a pin 34 which is in engagement with abore 37 in the lowermost of the cam disks.

At its upper end sleeve 35 is provided with a recess 38 which slidinglyreceives the lower end 39 of a manipulating member or sleeve 40 foraxial and rotary adjustment. The pattern disks 27 and 28 forstitch'length are secured to the lower end 39 of the manipulating memberor sleeve 49 which is provided with a shoulder or ring 41 at its lower`inner end for supporting a helical spring 43 which is disposed around acylindrical lock member 42. The other end of spring 43 is supportedagainst the head 44 of the lock member which is provided with a threadedbore 45 for engagement with a thread on the reduced upper p0rtion 46 ofthe shaft 29.

The nest of cam disks 36 for the lateral needle deflections ispreferably provided with three pins 47 distributed evenly around thecircumference of a circle which is concentric with the axis of rotation(FIGS. 3 and'4), which pins are in engagement with corresponding bores48 which extend through both cam disks 27 and 28. In addition to bores48 other through bores 48 are provided which are displaced by 30 withrespect to bores 48. This makes it possible to displace the cam disks 27and 28 with respect to the pattern disks 36 for the lateral needledeflections by 30, 120, 150, 240 and 270 degrees. This operation iseffected by raising the sleeve 40 against the tension of spring 43,which removes the cam disks 27 and 28 from the pins 47 for rotation tothe next throughgoing groups of apertures 48 or 48.

Besides the two aforementioned groups, two additional groups ofapertures 49 and 49 are provided, spaced from each other by 30, whichare only provided in disk 28. If the cam disks 27 and 28 are now shiftedin the same manner by means of the manipulating sleeve 40 and are placedupon pins 47 with the bores 49 or 49 which do not go through disks 27,the cam disks will assume a raised position of an amount correspondingto the thickness of a disk, thus causing the follower 26 which isrockable only in one plane to engage the lower cam disk 28 (FIG. 5). Aplurality of groups of holes such as 49 and 49 makes it possible in thesamemanner as set forth above to set up a predetermined phaserelationship of the pattern disk 23 with respect to the set of disks 36.

We claim: y

l. A guiding cam mechanism for Zig-zag sewing machines of the typehaving a laterally deectab-le needle bar and a material 'feed dogadapted to be guided by said cani mechanism, said mechanism includingneed-le bar cam follower means operatively connected to and adapted totransmit lateral deflection impulses to said needle bar and feed dog camfollower means including asingle follower member operatively connectedto and movable about a pivot in a single plane and adapted to transmitstitch length control impulses to said feed dog, said cam mechanismcomprising a cam shaft, a first group of rotatable cam disks mounted onsaid cam shaft for engagement by said feed dog cam follower means and asecond groupof rotatablefcam disks for engagement by said needle bar camfollower means mounted on said shaft coaxially with said first group,said first group being mounted around said shaft and being `axially andangularly adjustable relative to said second group and relative to saidfeed dog cam follower means, and setting means including a manipulatingmember mounted coaxially with said first group and operative to movesaid first group, thereby providing for optional phase displacementbetween said first group and said second group of Vdisks and for axiallymoving said first group to associate different cams yof said first groupwith said follower member.

Z, A guiding cam mechanism for Zig-zag sewing machines of the typehaving a laterally detlectable needle bar and a material feed dogadapted to be' guided by said cam mechanism, said mechanism includingneedle bar cam follower means operatively connected to and adapted totransmit lateral deflection impulses to said needle bar and feed dog camfollower means including a single follower member operatively connectedto and movable about a pivot in a single plane and adapted to transmitstitch length control impulses to said feed dog, said cam mechanismcomprising a cam shaft, a first group of rotatable cam disks mounted onsaid cam shaft for engagement by said feed dog cam follower means and asecond group of rotatable cam disks for engagement by said needle barcam follower means mounted on said shaft coaxially with said firstgroup, said first group being mounted aroundsaid shaft and being axiallyand angularly adjustable relative to said second group and relative tosaid feed dog cam follower means, and setting means including amanipulating member mounted coaxially with said first group andoperative to move said first group, thereby providing Ifor optionalphase displacement between said first group and said second group ofdisks and for axially moving said first group to associate differentcams of said first group with ,said follower member, one of said groupsof disks being provided with pins distributed evenly around a circleconcentric with the axis of rotation of the mechanism and the other ofsaid groups of disks having corresponding bores adapted to receive saidpins, said bores being provided in predetermined numbers of disks andextending into said disks t different depths.

3. A guiding cam mechanism for zig-Laag sewing machines of the typehaving a laterally deliectable needle bar and a material feed dogadapted to be guided by said cam mechanism, said mechanism Vincludingneedle bar cam follower means operatively connected to and adapted totransmit lateral deflection impulses to said nedle bar and feed dog camfollower means including a single follower member operatively connectedto and movable about a pivot in a single plane and adapted to transmitstitch length control impulses to said feed dog, said cam mechanismcomprising a cam shaft, a first group of rotatable cam disks mounted onsaid cam shaft for engagement by said feed dog cam follower means and asecond group'of rotatable cam disks for engagement by said needle barcam follower' means mounted on said shaft coaxially with said firstgroup, said first group being mounted around said shaft and beingaxially and angularly adjustable relative to said second group andrelative to said feed dog cam follower means, and setting meansincluding a manipulating member mounted coaxially with said first groupand operative to move said first group, thereby providing for optionalphase displacement between said first group and said second group ofdisks and for axially moving said first group to associate diderent camsof said first group with said follower member, one of said groups ofdisks being provided with pins distributed evenly around a circleconcentric with the axis of rotation of the mechanism and the other ofsaid groups ofdisks havingcorresponding bores adapted to receive saidpins, said bores being provided in predetermined numbers of disks andextending into said disks to different depths, the difference in depthbetween bores corresponding to the'thickness of the disks associatedwith the stitch length.

4. A guiding cam mechanism for zig-zag sewing machines of the typehaving a laterally deflectable needle bar and a material feed dogadaptedy to be guided by said cam mechanism, said mechanism includingneedle bar cam follower means operatively connected to yand adapted totransmit lateral deflection impulses to said needle bar and feed dog camfollower means including a single follower member operatively connectedto and movable about a pivot in a single plane and adapted to transmitstitch length control impulses to said feed dog, said cam mechanismcomprising a cam shaft, a

' lfirst group of rotatable cam disks mounted on said cam shaft forengagement by said feed dog cam Ifollower means and a second group ofrotatable oam disks for engagement by said needle bar cam follower meansmounted on said shaft coaxially with said first group, said first groupbeing mounted around said shaft and being axially and angularlyadjustable relative to said second group and relative to said feed dogcam `follower, means, and setting means including a manipulating membermounted coaXially with said firstgroup and operative to move said firstgroup, thereby providing for optional phase displacement between saidfirst group and said second group of disks and for axially moving saidfirst gro-up to associate different cams of said first group with saidfollower member, said first group of disks being associated with saidmechanism for transmitting the" stitch length control impulses and'being mounted above said second group of disks, and said manipulatingmember including a spring biased sleeve supporting said first group ofdisks and being axially and angularly movable relative to said secondgroup.

5. A guiding cam mechanism for Zig-zag sewing maohines of the typehaving Ia laterally deflectable needle bar and a material feed dogadapted to be guided by said cam mechanism, said mechanism' includingneedle bar cam follower means operatively connected to and adapted totransmit lateral deflection impulses to said needle bar and feed dog camfollower means including a single follower member operatively connectedto and movable about la pivot in a single plane and adapted to transmitstitch length control impulses to said feed dog, said cam mechanismcomprising a cam shaft, a first group of rotatable cam disks mounted onsaid cam shaft for engagement by said feed dog cam follower means and asecond :group of rotatable cam disks for engagement by said needle barcam follower' means mounted on said shaft coaxially with said rst group,said first group being mounted laround said shaft and being axially andangularly adjustable relative to said second group Iand relative to saidVfeed dog cam follower means, and setting means including a manipulatingmember mounted coaxially with said first group and operative to movesaid first group, thereby providing for optional phase displacementbetween said first group and said second group of disks and for axiallymoving said first group 'to associate different cams of said first group.with said follower member, one of said groups of disks being providedwith pins distributed evenly around a' circle concentric with the axisof rotation of the mechanism and the other of said groups of diskshaving corresponding bores 'adapted to receive said pins, said boresbeing provided in predetermined numbers of groups and extending intosaid groups to different depths, said rst group of disks beingassociated with said mechanism for transmitting the stitch lengthcontrol impulses and being mounted above said second group of disks, andsaid manipulating member including `a spring biased sleeve supportingsaid lfirst group of disks and being axially and angularly movablerelative to said second group.

References Cited in the le of this patent UNITED STATES PATENTS ItalyJuly 8, 1955

